New isoquinoline alkaloids will be isolated from plants, and then tested for anti-cancer activity. Their structures will also be elucidated. A variety of isoquinolines including spirobenzylisoquinolines, 13-oxoprotopines, phthalideisoquinolines, and aporphine-pavine dimers will be synthesized. The compounds we prepared will be tested for anti-cancer activity. New methods for the synthesis of diaryl ethers will be developed.